Downcast supports several playback speeds and allows a default speed to be set globally as well as per-podcast subscription.
The podcast episode player view contains a play speed button that, when tapped, will cycle through all available playback speeds. Tapping and holding the play speed button will present a list of available speeds for quickly selecting another speed.
Additionally, the speeds that are selected when tapping the playback speed button can be configured both globally and per-podcast now.
Where is 1.75x?
Unfortunately, the Apple framework we use for playback does not currently support 1.75x. We don't know why but if it ever does support this speed, we will add support for it.